<#--上下文变量-->
<#assign contextPath = request.contextPath/><!DOCTYPE HTML>
<#assign ipport = "localhost:8081"/><!DOCTYPE HTML>


<HTML>
<HEAD>
    <meta charset="utf-8">
    <TITLE>测试首页</TITLE>
    <link rel="stylesheet" href="${pageContext.request.contextPath}/webjars/bootstrap/3.3.7-1/css/bootstrap.min.css"/>
    <script src="${pageContext.request.contextPath}/webjars/jquery/3.1.1/jquery.min.js"></script>
    <script src="${pageContext.request.contextPath}/webjars/bootstrap/3.3.7-1/js/bootstrap.min.js"></script>
</HEAD>
<body>
Welcome<br/>
<input id="text" type="text" />
<div id="request">${request}<br/></div>
<div id="contextPath">${contextPath}<br/></div>
<div id="ipport">${ipport}<br/></div>

<button onclick="send()">发送消息</button>
<hr/>
<button onclick="closeWebSocket()">关闭WebSocket连接</button>
<hr/>
<div id="message">信息窗口<br/></div>
</body>

<SCRIPT>
    var websocket = null;
    //判断当前浏览器是否支持WebSocket
    if('WebSocket' in window) {
        //建立连接
        websocket = new WebSocket("ws://localhost:8081/websocketdemo/webSocketServer/1");
    } else {
        alert('当前浏览器 Not support websocket')
    }

    //连接发生错误的回调方法
    websocket.onerror = function() {
        setMessageInnerHTML("WebSocket连接发生错误");
    };

    //连接成功建立的回调方法
    websocket.onopen = function() {
        setMessageInnerHTML("WebSocket连接成功");
    }
    var U01data, Uidata, Usdata
    //接收到消息的回调方法
    websocket.onmessage = function(event) {
        console.log(event);
        setMessageInnerHTML(event.data);
    }

    //连接关闭的回调方法
    websocket.onclose = function() {
        setMessageInnerHTML("WebSocket连接关闭");
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function() {
        closeWebSocket();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        //在信息窗口拼接然后换行
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

    //关闭WebSocket连接
    function closeWebSocket() {
        websocket.close();
    }

    //发送消息
    function send() {
        var message = document.getElementById('text').value;
        websocket.send(message);
        setMessageInnerHTML(message );
    }
</SCRIPT>
</HTML>
